1. Field of the Invention
The present invention relates to a video signal processing device, a video signal processing method, and a non-transitory computer readable medium storing a video signal processing program. In particular, the present invention relates to a video signal processing device, a video signal processing method, and a non-transitory computer readable medium storing a video signal processing program for performing motion estimation and motion compensation of a video signal to be input.
2. Description of Related Art
Japanese Unexamined Patent Application Publication No. 2008-118505 discloses a technique relating to a frame rate converter (FRC) of motion compensation type. Frame rate conversion is a technique used to generate an interpolation frame to be displayed between one frame and another frame displayed subsequent to the one frame in a moving image, based on these frames. The frame rate conversion technique produces an effect that a target motion in a moving image to be displayed can be reproduced more smoothly by generating an interpolation frame to be inserted between frames. In this regard, Japanese Unexamined Patent Application Publication No. 2008-118505 discloses a technique relating to an image displaying device or the like for suppressing a disturbance or distortion of an insertion image in the vicinity of an effective image edge portion such as an edge portion of a screen caused by the frame rate conversion processing of motion compensation type. The image displaying device disclosed in Japanese Unexamined Patent Application Publication No. 2008-118505 includes a motion vector detection circuit for detecting a motion vector of an input image signal, an effective image edge portion judging circuit for judging if a motion vector detecting position is adjacent to the effective image edge portion, and a vector switching circuit for switching a vector in accordance with the judging result of the effective image edge portion judging circuit. The vector switching circuit fixes the vector to 0 vector in the case where the motion vector detecting position is adjacent to the effective image edge portion. In the case where the position is in other region, the vector switching circuit outputs the motion vector detected by the motion vector detection circuit to an insertion vector allocation circuit.
Japanese Unexamined Patent Application Publication No. 2006-304266 discloses a technique relating to a frame rate conversion processing device capable of obtaining a smooth reproduced image. The frame rate conversion processing device disclosed in Japanese Unexamined Patent Application Publication No. 2006-304266 includes pan/tilt determining means which determines whether an image is in a pan/tilt state on the basis of information related to motion of the image detected by motion detecting means for each frame of a moving image, moving distance setting means which sets 0 as a moving distance of an image with respect to a frame the image of which is not determined as an image in a pan/tilt state by the pan/tilt determining means, which calculates a moving distance of an image from the information related to the motion of the image detected by the motion detecting means with respect to a frame the image of which is determined as an image in a pan/tilt state, and which sets the obtained moving distance as a moving distance of the image, and prediction image generating means which generates a prediction image necessary for frame rate conversion on the basis of the moving distance of the image set for each frame by the moving distance setting means.
As for display modes of display devices such as television sets and monitors, there are two modes, i.e., progressive and interlace. Further, progressive signals and interlaced signals are used as video signal formats corresponding to these display modes. Note that a related application by the same inventor is Japanese Unexamined Patent Application Publication No. 2010-124193, which relates to IP (Interlace-Progressive) conversion.